Zika Virus Risk: The Latest Numbers

The findings revealed a 21% increase in the number of counties with Zika-carrying mosquitoes.

HealthDay News — Mosquitoes that can spread Zika, dengue, and chikungunya viruses are in more counties in the southern United States than previously thought, according to a study published online in the Journal of Medical Entomology.

The US Centers for Disease Control and Prevention conducted a mosquito survey in spring 2016. At the end of last year, the research team conducted a follow-up survey of mosquito control agencies, university researchers, and state and local health departments. That survey included Zika-bearing mosquito information from 38 new counties. The total body of evidence now runs from 1995 to 2016.

The findings revealed a 21% increase in the number of counties with Zika-carrying mosquitoes (Aedes aegypti). There was also a 10% increase in counties with dengue-spreading mosquitoes (Aedes albopictus).

Since 1995, the Zika-bearing mosquito has been documented in all states in the southern United States, with the most widespread county-level distributions in southern California, Arizona, Texas, Louisiana, and Florida. Additional counties with evidence of dengue-spreading mosquitoes are primarily in Kansas, Texas, Mississippi, Arkansas, and North Carolina, according to the report. Meanwhile, counties with both types of mosquito were located mostly in southern California, Arizona, Texas, Florida, and Maryland.